1. Field of the Invention
The present invention relates to a monitor area setting device, and in particular, to an improvement of a monitor area setting device that generates area setting information for designating a monitor area to an area monitoring sensor that emits detection light in different directions and senses an intruder within the previously set monitor area based on reflection of the detection light.
2. Description of the Related Art
Area monitoring sensors have been known as a sensor that senses an intruder such as a person entered into a no entrance area and outputs a detection signal. A typical area monitoring sensor is provided with, for example, a light projecting unit that projects detection light, a scanning unit that scans the detection light, and a light receiving unit that receives the detection light reflected on the intruder, and a distance and a direction toward the intruder are sensed based on an output from the light receiving unit. Then, based on a result of the sensing, it is determined whether or not the intruder is present within a predetermined area, and the detection signal is outputted based on a result of the determination. This detection signal is used, for example, as a control signal that stops a machine tool working near the monitored area.
Typically, an area setting tool is used in order to specify an area for sensing as a monitor area to such an area monitoring sensor, or in order to edit the monitor area that has been set. The area setting tool is an application program that runs on an information processing unit such as a personal computer, and can set a monitor area according to how factory equipment such as machine tools are placed.
In the case of a conventional area setting tool, however, the monitor area is set by an area that is enclosed by lines or arcs connecting vertices. Accordingly, it is not easy to add or delete a user specified area to or from the monitor area after setting a predetermined area as the monitor area. In particular, it is in fact difficult to add an area that is distant from the monitor area that has already been set, or delete an area that is within the monitor area but distant from a periphery portion of the monitor area.
In addition, the area monitoring sensor as described above, by its nature, cannot set an area that is positioned, with respect to the sensor, on a forward side of the area for sensing as a non-sensing area, or cannot set an area that is positioned, with respect to the sensor, on a backward side of the non-sensing area as an area for sensing. As a result, when editing the monitor area with the conventional area setting tool, it is adversely required to consider such characteristics of the area monitoring sensor when adding or deleting an area, which results in poor operability.